By George Harvey
The Fore Street Garage (FSG) in downtown Portland, Maine, has a new solar canopy. It was built as a collaborative effort by ReVision Energy, Quest Renewables, and East Brown Cow, a management company.
In many ways, it is hard to imagine a better site for a solar array than the top floor of a parking garage. For starters, parking garages with elevated top floors have a good chance of getting full sun for most of the day. They often are taller than whatever trees are around.
Very often, a proposed rooftop system cannot be installed because the roof is not designed to take the extra weight a solar array puts on it. If that sounds odd because solar panels are light, remember that solar panels can catch the wind, and so they have to be secured. On a flat rooftop, this may mean that the panels need to be ballasted to hold them, and this adds weight. However, a parking garage, which is designed to take the weight of many vehicles, is not likely to have such a problem.
The list of advantages for installing on a parking garage goes on. There are very few people who would raise aesthetic objections to putting a solar array on a parking area. The array shields the cars that park beneath it from the sun and prevents them from overheating. And we have not even gotten to the electricity produced.
The FSG array is made up of 578 solar panels, each of 335 watts. This provides 193.63 kilowatts of capacity. Quest Renewables designed the array. It is provided with seven of their Quadpod canopy systems. Each of these has its own inverter, which is grid-tied independently.
The Quadpod systems are interesting on their own. They are not assembled on the roof of the structure. Instead, they are largely assembled and wired, even to include most of the lighting, on the ground. Once the work that can be done on the ground is finished, they are hoisted to the top of the parking garage, and the installation is finished there. Two 270-ton cranes were used for the purpose at FSG.
There are numerous advantages to this approach. It means that workers spend more time on the ground, and this improves both productivity and safety. It can also make installation faster. Using the Quadpods shortened the work schedule, reducing down-time for the parking areas involved.
“Quest Renewables’ innovative QuadPod solar canopy allowed us to meet a very aggressive schedule at a particularly challenging site, Fortunat Mueller, ReVision Energy’s managing partner and one of its founders, said. He added, “The Quest team was terrific to work with from start to finish.”
Eastern Brown Cow, which owns the FSG array, also owns the nearby Hyatt Place Portland-Old Port Hotel. Guests can park their cars on the top floor of the parking garage, where the array is installed. One advantage they have, in addition to parking in the shade of the solar array, is access to electric car chargers.
The FSG array is grid-tied, supplying power to the Hyatt Place Hotel. It is expected that the array will produce over 230 megawatt hours of electricity each year. This should offset at least 20% of the hotel’s electric demand. When the array delivers more power than the hotel can use, the excess is sent to the grid.
The FSG array was built with support from the federal government. The cost of the system was offset 30% by tax credits.
The idea of a solar canopy on a parking garage is not new. It has been done many times in other places. Here in the Northeast, it has only slowly caught on, however, and this can be attributed in large part to the fact that the area has historically been less than ideal for solar power. In fact, the FSG array is the first of its kind in Maine.
With the rapid decline in the costs of solar systems, we can be sure to see more arrays of this type installed. And with the rapid decline in large storage batteries, the pace of solar installation can be expected to increase even more.